Step-by-step explanation:
there is not much work to show, because there is not much work to do ...
the temperature fell from 20F to -5F.
so it fell by 20 - -5 = 20 + 5 = 25 degrees.
that's it.
the result is not very surprising, is it, because first it fell all the 20 positive degrees and then the 5 negative degrees. so, altogether the temperature fell in total by 25 degrees.
